- Gold(I) iodide catalyzed sonogashira reactions
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Gold(I) iodide catalyzed Sonogashira reactions have been developed. Terminal alkynes reacted with aryl iodides and bromides smoothly in the presence of AuI (1 mol-%) and dppf (1 mol-%) in toluene to generate the corresponding cross-coupling products in good to excellent yields. Furthermore, aromatic terminal alkynes could also react with 2-iodoaniline to form substituted indoles in excellent yields through a coupling-cyclization reaction sequence under the present reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
- Li, Pinhua,Wang, Lei,Wang, Min,You, Feng
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Read Online
- γ-Valerolactone as an alternative biomass-derived medium for the Sonogashira reaction
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γ-Valerolactone (GVL) can be used as an efficient and practical alternative to the banned and commonly used dipolar aprotic solvents. In this contribution GVL has been used as a non-toxic, biodegradable, biomass-derived medium, for the definition of a sim
- Strappaveccia, Giacomo,Luciani, Lorenzo,Bartollini, Elena,Marrocchi, Assunta,Pizzo, Ferdinando,Vaccaro, Luigi
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- Catalytic efficiency of a new tridentate ferrocenyl phosphine auxiliary: Sonogashira cross-coupling reactions of alkynes with aryl bromides and chlorides at low catalyst loadings of 10-1 to 10-4 Mol %
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(Chemical Equation Presented) The catalytic activity in Sonogashira cross-coupling reactions of alkynes with a variety of aryl halides (including chlorides) using a multidentate ferrocenyl phosphine is presented. The novel mixed ferrocenyl aryl/alkyl trip
- Hierso, Jean-Cyrille,Fihri, Aziz,Amardeil, Regine,Meunier, Philippe,Doucet, Henri,Santelli, Maurice,Ivanov, Vladimir V.
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- Palladium Nanoparticles Supported on a Porous Organic Polymer: An Efficient Catalyst for Suzuki-Miyaura and Sonogashira Coupling Reactions
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A new porous organic polymer (POP) with high thermal stability and large surface area has been synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP was characterized by XRD, TGA, SEM and TEM. The catalyst consists of highly dispersed palladium nanoparticles of 0.9-4 nm size on POP with a large surface area of 650 m2/g. It presents high catalytic activity for Suzuki-Miyaura and Sonogashira reactions. The catalyst was reusable for three to five times without significant loss of activity. A new porous organic polymer (POP) was synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP exhibits high catalytic activity for Suzuki-Miyaura and Sonogashira reactions and is reusable in these heterogeneous catalytic reactions.
- Ren, Xiaomeng,Kong, Shengnan,Shu, Qiding,Shu, Mouhai
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Read Online
- Decarbonylative Sonogashira Cross-Coupling of Carboxylic Acids
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Decarbonylative Sonogashira cross-coupling of carboxylic acids by palladium catalysis is presented. The carboxylic acid is activated in situ by the formation of a mixed anhydride and further decarbonylates using the Pd(OAc)2/Xantphos system to provide an aryl-Pd intermediate, which is intercepted by alkynes to access the traditional Pd(0)/(II) cycle using carboxylic acids as ubiquitous and orthogonal electrophilic cross-coupling partners. The methodology efficiently constructs new C(sp2)-C(sp) bonds and can be applied to the derivatization of pharmaceuticals. Mechanistic studies give support to decarbonylation preceding transmetalation in this process.
- Liu, Chengwei,Szostak, Michal
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supporting information
p. 4726 - 4730
(2021/06/28)
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- Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes
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Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes is described. This reaction not only effectively inhibits the formation of undesired homocoupled products by avoiding the addition of a base, but also exhibits a wide substrate scope to provide a general access to diverse unsymmetrical diarylethynes.
- Chen, Qiang,Fu, Liyan,Nishihara, Yasushi
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supporting information
p. 7977 - 7980
(2020/09/09)
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- Porous organic polymer with: In situ generated palladium nanoparticles as a phase-transfer catalyst for Sonogashira cross-coupling reaction in water
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A new Pd nanoparticle loaded and imidazolium-ionic liquid decorated organic polymer of Pd@PTC-POP was readily fabricated via a Pd(PPh3)4 catalysed in situ one-pot Suzuki cross-coupling reaction between imidazolium attached dibromoben
- Dong, Ying,Chen, Yun-Qi,Jv, Jing-Jing,Li, Yue,Li, Wen-Han,Dong, Yu-Bin
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p. 21671 - 21678
(2019/07/30)
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- A palladium catalyzed aryl alkyne preparation method
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The invention discloses a palladium catalyzed aryl alkyne of the preparation method, comprises the following steps: in the catalyst, under the action of the ligand and alkali, substituted with aryl sulfonyl chloride alkynoic occurs in the organic solvent escapes suosuo the coupling reaction, after the reaction is finished after treatment to obtain the aryl alkyne. Used in the preparation method of the cheap raw material, the reaction and simple post treatment operation, at the same time, the reaction less side reaction, high yield of the product.
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Paragraph 0037; 0038; 0039
(2019/05/21)
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- A phosphine-free, atom-efficient cross-coupling of aryl iodides with triarylindiums or trialkynylindiums catalyzed by immobilization of palladium(0) in MCM-41
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The first phosphine-free heterogeneous atom-efficient cross-coupling reaction of aryl iodides with triarylindiums or trialkynylindiums was achieved in THF at 68 °C by using 1 mol% of MCM-41-immobilized palladium(0)-Schiff base complex [MCM-41-N,N-Pd(0)] as catalyst, yielding a variety of unsymmetrical biaryls and arylalkynes in good to excellent yields. The heterogeneous palladium(0) catalyst could easily be prepared via a simple procedure from commercially readily available reagents, and recovered by filtration of the reaction solution and recycled at least 10 times without significant loss of activity.
- Lei, Zhiwei,Liu, Haiyi,Cai, Mingzhong
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- Three-Component One-Pot Synthesis of Unsymmetrical Diarylalkynes by Thermocontrolled Sequential Sonogashira Reactions Using Potassium Ethynyltrifluoroborate
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Unsymmetrical diarylalkynes were synthesized in moderate to good yields through a three-component one-pot procedure involving thermocontrolled sequential Sonogashira reactions with potassium ethynyltrifluoroborate and two different reactive aryl halides. The one-pot procedure was initiated by the palladium/copper-catalyzed Sonogashira coupling of potassium ethynyltrifluoroborate to an aryl iodide or electron-deficient aryl bromide at 40 °C. Following a subsequent deboronative Sonogashira reaction of the in situ generated potassium (arylethynyl)trifluoroborate, a second coupling to a less-active electron-rich aryl bromide at 80 °C, without any additional palladium/copper catalyst or base, gave rise to unsymmetrical diarylalkynes.
- Kim, Taejung,Jeong, Kyu Hyuk,Kim, Youngseok,Noh, Taesub,Choi, Jaeyoung,Ham, Jungyeob
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p. 2425 - 2431
(2017/05/12)
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- Further insight into the photochemical behavior of 3-aryl-N-(arylsulfonyl)propiolamides: tunable synthetic route to phenanthrenes
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Reported herein is further insight into the photochemical behaviour of 3-aryl-N-(arylsulfonyl)-propiolamides, which provides a straightforward way to access meaningful phenanthrenes. Mechanistic investigation indicated that aryl migration, C-C coupling, 1,3-hydrogen shift, desulfonylation and elimination were involved in the process. Moreover, this protocol allowed for scale-up using a flow reactor.
- Chen, Ming,Zhao, Xinxin,Yang, Chao,Wang, Yanpei,Xia, Wujiong
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p. 12022 - 12026
(2017/03/01)
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- Functionalized α,β-ynones: Efficient ligand for Cu catalyzed Sonogashira-type cross-coupling reaction
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Under the classic reaction conditions, a large excess of copper catalyst and N, O donor ligands were mandatory for the catalytic cross-coupling of Csp2-Csp bonds. Herein, we wish to report α,β-ynones as σ-, π-electron donating ligands for copper catalyzed Sonogashira-type reaction. As low as 0.25-2.5 mol% of L11 (3-(4-bromophenyl)-1-(4-methoxyphenyl)prop-2-yn-1-one) significantly accelerated the 0.1-1.0 mol% of CuI catalyzed cross-coupling of aryl iodides with terminal alkynes and alkynylcarboxylic acids, respectively. This low-mol% catalyst system showed satisfactory activity and tolerance with 36 examples of substituted alkynes.
- Wang, Xian,Wang, Zhenhua,Xie, Zunyuan,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
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p. 109296 - 109300
(2016/11/30)
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- Scope and limitations of a DMF bio-alternative within Sonogashira cross-coupling and Cacchi-type annulation
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Pd-catalysed C-C bond formation is an essential tool within the pharmaceutical and agrochemical industries. Many of these reactions rely heavily on polar aprotic solvents; however, despite their utility, these solvents are incompatible with the drive towards more sustainable chemical synthesis. Herein, we describe the scope and limitations of an alternative to DMF derived from renewable sources (Cyrene) in Sonogashira cross-coupling and Cacchi-type annulations.
- Wilson, Kirsty L.,Kennedy, Alan R.,Murray, Jane,Greatrex, Ben,Jamieson, Craig,Watson, Allan J. B.
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supporting information
p. 2005 - 2011
(2016/10/05)
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- Copper-catalyzed C(sp2)-C(sp) Sonogashira-type cross-coupling reactions accelerated by polycyclic aromatic hydrocarbons
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Copper-catalyzed Sonogashira-type reactions were dramatically accelerated by introducing a catalytic amount of polycyclic aromatic hydrocarbon additive. This novel catalytic system features low copper loading (0.5mol% Cu 5mol%), broad reaction scope a
- Xu, Wei,Yu, Bo,Sun, Huaming,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
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p. 353 - 356
(2015/06/02)
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- MCM-41-immobilized Schiff base-pyridine bidentate copper(I) complex as a highly efficient and recyclable catalyst for the Sonogashira reaction
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Abstract A novel MCM-41-immobilized Schiff base-pyridine bidentate copper(I) complex [MCM-41-Sb,Py-CuI] was conveniently prepared from commercially available and inexpensive 3-aminopropyltriethoxysilane via immobilization on MCM-41, followed by reacting w
- Zhao, Hong,Huang, Bin,Wu, Yichao,Cai, Mingzhong
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- Recyclable and reusable NiCl2(PPh3)2/CuI/PEG-400/H2O system for the sonogashira coupling reaction of aryl iodides with alkynes
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A stable and highly efficient NiCl2(PPh3)2/CuI/PEG-400/H2O catalytic system for the Sonogashira reaction has been developed. In the presence of NiCl2(PPh3)2 and CuI, the coupling reaction of aryl iodides with terminal alkynes was carried out smoothly in a mixture of poly(ethylene glycol) (PEG-400) and water at 100C with K2CO3 as base to afford a variety of arylacetylenes in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether, and the NiCl2(PPh3)2/CuI/PEG-400/H2O system could be easily recycled and reused six times without significant loss of catalytic activity. Our system not only avoids the use of easily volatile organic solvents but also solves the basic problem of catalyst reuse.
- Wei, Ting,Zhang, Tingli,Huang, Bin,Tuo, Yuxin,Cai, Mingzhong
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p. 846 - 849
(2016/01/25)
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- Phosphane-ligated ionic palladium complexes: Synthesis, characterization and application as efficient and reusable precatalysts for the homogeneous carbonylative sonogashira reaction under CuI-free conditions
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The stable ionic PdII complexes 1A-4A were synthesized through the complexation of PdCl2(MeCN)2 with the phosphane-functionalized ionic liquids (FILs) 1-4 with π-acceptor character. Single-crystal X-ray diffraction analyses showed that 1A-4A were all composed of PdII-centred square-planar cations and triflate (OTf-, CF3SO3-) counteranions. The complex cations in 1A-3A possessed structural similarity to trans-PdCl2(PPh3)2. The cation in 4A was a new PdII-centered planar complex ligated by the phosphane-carbon anion-carbene (PCC) pincer in a tripodal manner. The stabilities of 1A-4A were improved due to the intensive π-backbonding interaction between the Pd and P atoms. When complexes 1A-4A were used as precatalysts for homogeneous carbonylative Sonogashira coupling of PhI with phenylacetylene free of CuI, 1A-3A exhibited excellent catalytic behaviour with a TON of up to 1700 at a CO pressure of 0.5 MPa and moderate temperature of 100 °C, whereas 4A exhibited poor activity towards the transformation of PhI due to the high stability of 4A. The recycling experiments of 3A in [Bpy]BF4 (as a solvent) indicated that 3A could be recycled for 5 runs with neither activity loss nor metal leaching into the organic phase. Complex 3A also proved to be a general precatalyst for the carbonylative Sonogashira couplings of a wide range of aryl iodides with phenylacetylene. The selectivity of the desired carbonylation product depended more on electronic effects than the steric effects of the substituents of the aryl iodides.
- Zhang, Jing,Wang, Yongyong,Zhao, Xiaoli,Liu, Ye
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p. 975 - 985
(2015/04/27)
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- Palladium supported on zinc oxide nanoparticles: Synthesis, characterization, and application as heterogeneous catalyst for Mizoroki-Heck and Sonogashira reactions under ligand-free and air atmosphere conditions
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In this paper, a novel Palladium (Pd) supported on ZnO nanoparticles was readily synthesized and characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and BET specific surface area measurement. The total amount of palladium particles on ZnO was determined by induced coupled plasma (ICP) analysis and atomic absorption spectroscopy (AAS) which is 9.8 wt%. Percentage of accessible Pd as active catalyst is also estimated to 2.72% based on the thermogravimetric (TG) analysis. Nano Pd/ZnO was found as a new, novel, and excellent heterogeneous catalyst for ligand-free C-C bond formation through the Mizoroki-Heck and Sonogashira reactions under air atmosphere without the use of any Ar or N2 flow. The catalyst can be recovered and recycled several times without marked loss of activity.
- Hosseini-Sarvari, Mona,Razmi, Zahra,Doroodmand, Mohammad Mehdi
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p. 477 - 486
(2014/03/21)
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- A functionalized ionic liquid containing phosphine-ligated palladium complex for the Sonogashira reactions under aerobic and CuI-free conditions
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A Pd-complex functionalized ionic liquid (IL), di-(1-butyl-2- diphenylphosphino-3-methylimidazolium)-dichloropalladium(II) hexafluorophosphate (2), was synthesized and used as the highly efficient and recyclable catalyst for the Sonogashira reactions of aryl iodides and aryl bromides with several terminal acetylenes, under aerobic and CuI-free conditions. The activity loss, Pd black precipitation, and Pd leaching were not observed even after 7 runs in 2-catalyzed Sonogashira reactions using the room temperature IL of [Bmim]PF 6 as the reaction medium.
- Zhang, Jing,Crossed, Dakovi? Marijana,Popovi?, Zora,Wu, Haihong,Liu, Ye
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scheme or table
p. 160 - 163
(2012/04/04)
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- Continuous flow coupling and decarboxylation reactions promoted by copper tubing
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A convenient and efficient flow method for Ullmann condensations, Sonogashira couplings, and decarboxylation reactions using a commercially available copper tube flow reactor (CTFR) is described. The heated CTFR effects these transformations without added metals (e.g., Pd), ligands, or reagents, and in greater than 90% yield in most cases examined.
- Zhang, Yun,Jamison, Timothy F.,Patel, Sejal,Mainolfi, Nello
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supporting information; experimental part
p. 280 - 283
(2011/04/15)
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- Transition-metal-free sonogashira-type coupling of ortho-substituted aryl and alkynyl grignard reagents by using 2,2,6,6-tetramethylpiperidine-N-oxyl radical as an oxidant
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Cross coupling of aryl, alkenyl, and alkynyl magnesium compounds by using 2,2,6,6-tetramethylpiperidine-N-oxyl radical (TEMPO) as an environmentally benign organic oxidant is described. This coupling reaction can be performed without adding any transition
- Maji, Modhu Sudan,Murarka, Sandip,Studer, Armido
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supporting information; experimental part
p. 3878 - 3881
(2010/11/17)
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- Highly selective semihydrogenation of phenylalkynes to (Z)-styrenes using hantzsch ester 1,4-dihydropyridine catalyzed by Pd/C
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Various alkynes have been selectively reduced to the corresponding Z-alkenes catalyzed by Pd/C using Hantzsch ester 1,4-dihydropyridine as the hydrogen source. Georg Thieme Verlag Stuttgart.
- Zhao, Yankai,Liu, Qiang,Li, Jing,Liu, Zhongquan,Zhou, Bo
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supporting information; experimental part
p. 1870 - 1872
(2010/10/04)
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- Palladium nanoparticles supported on MOF-5: A highly active catalyst for a ligand- and copper-free Sonogashira coupling reaction
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Palladium nanoparticles supported on MOF-5 (Pd/MOF-5), have been prepared by a chemical method at room temperature. MOF-5 and Pd/MOF-5 were characterized by X-ray diffraction, N2 sorption, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. The catalyst consists of highly dispersed palladium nanoparticles (about 3-6 nm) on MOF-5 with a high surface area (533 m2/g). It exhibits efficient catalytic activity for the Sonogashira coupling reaction between aryl iodides and terminal acetylenes without the assistance of ligand and copper.
- Gao, Shuixia,Zhao, Nan,Shu, Mouhai,Che, Shunai
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experimental part
p. 196 - 201
(2011/02/23)
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- Copper-catalyzed decarboxylative cross-coupling of alkynyl carboxylic acids with aryl halides
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The copper-catalyzed decarboxylative reactions of alkynyl carboxylic acids with aryl halides were performed under relatively mild reaction conditions. Benzofurans could be further prepared smoothly by a one-pot domino protocol on the basis of decarboxylative cross-coupling of 2-iodophenol.
- Zhao, Dongbing,Gao, Chao,Su, Xiaoyu,He, Yunqing,You, Jingsong,Xue, Ying
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supporting information; experimental part
p. 9049 - 9051
(2011/02/17)
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- Ligand-free sonogashira coupling reactions with heterogeneous Pd/C as the catalyst
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A variety of aryl iodides were coupled with aromatic and aliphatic terminal alkynes to give the corresponding 1,2-disubstituted aromatic alkynes in good yields by using only 0.4 mol % of the heterogeneous 10% Pd/C as the catalyst without a ligand, copper
- Mori, Shigeki,Yanase, Takayoshi,Aoyagi, Satoka,Monguchi, Yasunari,Maegawa, Tomohiro,Sajiki, Hironao
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supporting information; experimental part
p. 6994 - 6999
(2009/07/18)
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- New cyclopentadienyl, indenyl or fluorenyl substituted phosphine compounds and their use in catalytic reactions
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The invention is directed to a phosphine compound represented by general formula (1) wherein R' and R" independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R' and R" are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; Cps is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group. Also claimed is the use of these phosphines as ligands in catalytic reactions and the preparation of these phosphines.
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Page/Page column 42; 45
(2008/06/13)
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- MCM-41-supported bidentate phosphine palladium(0) complex: a highly active and recyclable catalyst for the Sonogashira reaction of aryl iodides
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The first MCM-41-supported bidentate phosphine palladium(0) complex has been prepared. This complex is a highly efficient catalyst for Sonogashira reaction and can be reused at least 10 times without any decrease in activity.
- Cai, Mingzhong,Sha, Junchao,Xu, Qiuhua
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p. 4642 - 4647
(2007/10/03)
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- 9-Fluorenylphosphines for the Pd-catalyzed Sonogashira, Suzuki, and Buchwald-Hartwig coupling reactions in organic solvents and water
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The lithiation/alkylation of fluorene leads to various 9-alkyl-fluorenes (alkyl = Me. Et, /Pr, -Pr. -C18H25) in > 95% yields, for which lithiation and reaction with R2PCl (R = Cy, iPr, tBu) generates 9-alkyl, 9-PR2fluorenes which constitute electron-rich and bulky phosphine ligands. The in-situ-formed palladium-phosphinc complexes ([Na2PdCl4], phosphonium salt, base, substrates) were tested in the Sonogashira. Suzuki, and Buchwald-Hartwig reactions of aryl chlorides and aryl bromides in organic solvents. The Sonogashira coupling of aryl chlorides at 100-120°C leads to >90% yields with 1 mol % of Pd catalyst. The Suzuki coupling of aryl chlorides typically requires 0.05 mol % of Pd catalyst at 100°C in dioxane for quantitative product formation. To carry out "green" cross-coupling reactions in water, 9-ethylfluorenyldicyclohexylphosphine was reacted in sulphuric acid to generate the respective 2-sulfonated phosphonium salt. The Suzuki coupling of activated aryl chlorides by using this water-soluble catalyst requires only 0.01 mol% of Pd catalyst, while a wide range of aryl chlorides can be quantitatively converted into the respective coupling products by using 0.1-0.5 mol % of catalyst in pure water at 100°C. Difficult substrate combinations, such as naphthylboronic acid or 3-pyridylboronic acid and aryl chlorides are coupled at 100°C by using 0.1-0.5 mol % of catalyst in pure water to obtain the respective N-heterocycles in quantitative yields. The copper-free aqueous Sonogashira coupling of aryl bromides generates the respective tolane derivatives in > 95 % yield.
- Fleckenstein, Christoph A.,Plenio, Herbert
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p. 2701 - 2716
(2008/03/14)
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- An amine-, copper- and phosphine-free Sonogashira coupling reaction catalyzed by immobilization of palladium in organic-inorganic hybrid materials
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An immobilization of palladium in organic-inorganic hybrid materials-catalyzed Sonogashira coupling reaction has been described. Terminal alkynes reacted with aryl iodides and aryl bromides only in the presence of a 3-(2-aminoethylamino)-propyl-functionalized, silica gel-immobilized palladium catalyst under amine-, copper- and phosphine-free reaction conditions. The reaction generates the corresponding cross-coupling products in excellent yields. Furthermore, the silica-supported palladium can be recovered and recycled by a simple filtration of the reaction solution and used for 30 consecutive trials without any decreases in activity.
- Li, Pin-Hua,Wang, Lei
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p. 681 - 685
(2007/10/03)
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- A novel silver iodide catalyzed sonogashira coupling reaction
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A novel and efficient Ag-catalyzed Sonogashira coupling reaction has been developed. Terminal alkynes couple with aryl iodides and aryl bromides in the presence of silver iodide, tri-phenylphosphine and potassium carbonate to afford the corresponding cross-coupling products in high yields. Georg Thieme Verlag Stuttgart.
- Li, Pinhua,Wang, Lei
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p. 2261 - 2265
(2007/10/03)
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- Can polarization of triple bond in tolanes be deduced from 13C NMR shifts? Re-evaluation of factors affecting regiochemistry of the palladium-catalyzed hydrostannation of alkynes
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Polarization of the triple bond in a series of differently substituted ortho and para-tolanes has been studied by NMR and computational methods in order to examine if 13C NMR data can be effectively used for the assessment of electronic polarization of a triple bond in diarylacetylenes. DFT calculations of both natural charges and NMR properties revealed that chemical shifts concur with effective charges on sp-carbon atoms in para-tolanes, whereas in ortho-analogues magnetic anisotropy complicates the analysis making 13C NMR data inapplicable for ascribing triple bond polarization. The obtained information was used to reevaluate factors affecting the regiochemistry of the Pd-catalyzed hydrostannation of the triple bond in tolanes. Computational study on the polarization of triple bonds taken together with the experimental data on hydrostannation of various mono- and disubstituted tolanes bearing para- and ortho-substituents demonstrated that the regioselectivity of hydrostannation is governed by a combination of electronic and steric factors. In para-tolanes, the electronic effect prevails and α- and β-vinylstannanes are obtained predominantly for substrates with electron-withdrawing and electron-donating groups, respectively. In the ortho-series, steric factors dominate over electronics and α-isomers are produced with high selectivity regardless of the substituents' nature. However, it was found that in disubstituted "push-pull" tolanes steric control of an ortho-group can be overruled by the very strong electronic effect of an electron-withdrawing substituent in para-position.
- Rubin, Michael,Trofimov, Alexander,Gevorgyan, Vladimir
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p. 10243 - 10249
(2007/10/03)
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- Application of recoverable nanosized palladium(0) catalyst in Sonogashira reaction
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In the absence of ligand, copper and amine, a recoverable nanoparticle palladium(0) catalyzed Sonogashira reaction of aryl iodides and bromides with terminal alkynes was developed. The protocol involved the use of an environmental-friendly reaction system with ethanol as the solvent, potassium carbonate as a base, and poly(vinylpyrrolidone) (PVP) supported nanosized palladium metal colloids as the catalyst. The palladium metal was recovered and recycled by a simple decantation of the reaction solution and used for eight consecutive trials without significant loss of its reactivity.
- Li, Pinhua,Wang, Lei,Li, Hongji
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p. 8633 - 8640
(2007/10/03)
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- Easy copper-, ligand- and amine-free sonogashira coupling reaction catalyzed by palladium on carbon at low catalyst loading and by exposure to air
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An easy copper-, ligand and amine-free Sonogashira coupling reaction catalyzed by commercially available palladium on carbon with air at low catalyst loading (0.2 mol% Pd) has been developed. Aryl iodides coupled with aromatic alkynes gave good to excelle
- Zhang, Guolin
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p. 619 - 622
(2007/10/03)
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- A convenient high activity catalyst for the Sonogashira coupling of aryl bromides
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A mixture of Na2PdCl4, CuI and (t-Bu) 3PH+BF4- (molar ratio 4:3:8) dispersed in H2N(i-Pr)2 Br can be used as a "single source" precatalyst for the Sonogashira coupling of aryl bromides with various aryl- and alkylacetylenes in HN(i-Pr)2 solvent. Arylacetylenes require just 0.005 mol % of Pd catalyst at 80°C, with TOFs ranging between 3,200 and 10,000 h-1.
- Koellhofer, Axel,Plenio, Herbert
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p. 1295 - 1300
(2007/10/03)
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- Sonogashira cross-coupling reactions of aryl chlorides with alkynes catalysed by a tetraphosphine-palladium catalyst
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A range of aryl chlorides undergoes cross-couplings with alkynes in good yields in the presence of [PdCl(C3H5)]2/cis, cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as catalyst. A variety of aryl chlorides such as chloroacetophenone, chlorobenzonitrile, chloronitrobenzene, chloroanisole or chlorotoluene have been used successfully. The reaction also tolerates several alkynes such as phenylacetylene, dec-1-yne, ethynylcyclohexene or alk-1-ynols. Furthermore, this catalyst can be used at low loading with some substrates.
- Feuerstein, Marie,Doucet, Henri,Santelli, Maurice
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p. 8443 - 8446
(2007/10/03)
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- Palladium-tetraphosphine complex: An efficient catalyst for the alkynylation of ortho-substituted aryl bromides
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The tetraphosphine cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane in combination with [Pd(C3H5)Cl]2 affords a very efficient catalyst for the alkynylation of ortho-substituted aryl bromides. A wide variety of substituents such as phenyl, trifluoromethyl, acetyl, formyl or nitrile, are tolerated. High turnover numbers can be obtained with most of these aryl bromides. The coupling of sterically very congested aryl bromides such as 9-bromoanthracene or 2,4,6-triisopropylbromobenzene also proceeds in good yields.
- Feuerstein, Marie,Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 1281 - 1289
(2007/10/03)
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- Palladium-tetraphosphine complex: An efficient catalyst for the coupling of aryl halides with alkynes
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A study was performed on palladium-tetraphosphine complex which is an efficient catalyst for the coupling of aryl halides with alkynes. It was found that a turnover number of 2600000 can be obtained for the reaction of 4-trifluoro-methylbromobenzene with phenylacetylene in the presence of this catalyst. It was also found that the catalyst is more efficient than the complex formed with a triphenylphosphine ligand.
- Feuerstein, Marie,Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 2235 - 2237
(2007/10/03)
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- An iminophosphine-palladium catalyst for cross-coupling of aryl halides with organostannanes
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A palladium complex bearing iminophosphine ligand, N-(2- diphenylphosphinobenzylidene)-2-phenylethylamine (1), was found to be more catalytically active than others for the cross-coupling of various types of aryl halides with alkynyl-, alkenyl- and arylstannanes to give the corresponding coupling products in high yields.
- Shirakawa, Eiji,Yoshida, Hiroto,Takaya, Hidemasa
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p. 3759 - 3762
(2007/10/03)
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